Shift Lock Control System Buick Century VI

Scheme 398

Scheme 399

Scheme 400

Scheme 401

Scheme 402

Automatic Transmission Shift Lock Control Connector End Views

A/T Shift Lock Control Solenoid Connector End Views (Century) Connector Part Information 12052832 2-Way F Metri-Pack 150 Series (BLK) Pin Wire Color Circuit No. Function A DK GRN/ WHT 1135 A/T Shift Lock Control Solenoid Supply Voltage B BLK 150 Ground

A/T Shift Lock Control Switch Connector End Views (Regal) Connector Part Information 12064762 6-Way F Metri-Pack 150 Series (GRY) Pin Wire Color Circuit No. Function A ORN/BLK 434 Neutral Safety Switch Signal B PNK 1439 Ignition 1 Voltage C LT BLU 1134 Ignition Lock Cylinder Control Actuator Signal D - - Not Used E DK GRN/WHT 1135 A/T Shift Lock Control Solenoid Supply Voltage F PPL 1600 Ignition 0 Voltage

Brake to Shift Relay Connector End Views Connector Part Information 12129715 6-Way F Metri-Pack 280 Series Flexlock (MD GRY) Pin Wire Color Circuit No. Function A1 PNK 1439 Ignition 1 Voltage PNK 1439 Ignition 1 Voltage (Regal) A2 ORN/BLK 434 Neutral Safety Switch Signal B1-B2 - - Not Used C1 BLK 1550 Ground C2 TAN/WHT 816 A/T Shift Lock Solenoid Supply Voltage

Diagnostic Starting Point - Automatic Transmission Shift Lock Control

Begin the system diagnosis with the Diagnostic System Check - Automatic Transmission Shift Lock Control . The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
2. 5: The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

Diagnostic System Check - Automatic Transmission Shift Lock Control

Scan Tool Output Controls

Scan Tool Output Controls

Scan Tool Data List

Body Control Module (BCM) Scan Tool Data List

Powertrain Control Module (PCM) Scan Tool Data List

Diagnostic Trouble Code (DTC) List

Diagnostic Trouble Code (DTC) List

Circuit Description

The body control module (BCM) controls the brake to shift relay control circuit and monitors the voltage of the control circuit.

Conditions for Running the DTC

The ignition is in the ON position.

Conditions for Setting the DTC

1. The body control module (BCM) detects the brake to shift relay control circuit voltage is at or below 1.5 volts in the OFF state.
2. The condition above must be present for more than 0.3 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B2707 in memory.

Conditions for Clearing the DTC

1. A current DTC B2707 will clear if the short to ground or open in the brake to shift relay control circuit is no longer detected by the body control module (BCM) or after one ignition cycle.
2. A history DTC B2707 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
3. A scan tool may be used to clear the DTC.

Diagnostic Aids

1. If DTC B2707 is a history DTC, the fault may be intermittent. Refer to «Testing for Intermittent Conditions and Poor Connections»(ref-188239-S05445184952005090100000) in Wiring Systems.
2. The following conditions may cause an intermittent malfunction to occur: An intermittent short to ground or open in the brake to shift relay control circuit. The brake to shift relay is intermittently shorted to ground internally. The body control module (BCM) is intermittently shorted to ground internally.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Listen for an audible click when the brake to shift relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
2. 3: Tests for voltage at the brake to shift relay.
3. 4: Verifies that the body control module (BCM) is providing ground to the control circuit of the brake to shift relay.
4. 5: Tests if ground is constantly being applied to the brake to shift relay control circuit.
5. 12: The body control module must be programmed for the vehicle RPO configuration.

DTC B2707

The body control module (BCM) controls the brake to shift relay control circuit and monitors the voltage of the control circuit.

The ignition is in the ON position.

1. The body control module (BCM) detects the brake to shift relay control circuit voltage is at or above 8.0 volts in the ON state.
2. The condition above must be present for more than 0.3 seconds.

The BCM stores DTC B2708 in memory.

1. A current DTC B2708 will clear if the short to voltage in the brake to shift relay control circuit is no longer detected by the body control module (BCM) or after one ignition cycle.
2. A history DTC B2708 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
3. A scan tool may be used to clear the DTC.

1. If DTC B2708 is a history DTC, the fault may be intermittent. Refer to «Testing for Intermittent Conditions and Poor Connections»(ref-188239-S05445184952005090100000) in Wiring Systems.
2. The following conditions may cause an intermittent malfunction to occur: An intermittent short to voltage in the brake to shift relay control circuit. The brake to shift relay is intermittently shorted to voltage internally. The body control module (BCM) is intermittently shorted to voltage internally.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Listen for an audible click when the brake to shift relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
2. 3: Verifies that the body control module (BCM) is providing ground to the control circuit of the brake to shift relay.
3. 4: Tests if short to battery voltages is present.
4. 5: Tests if the brake to shift relay control circuit is open.
5. 11: The body control module must be programmed for the vehicle RPO configuration.

DTC B2708

Symptoms - Automatic Transmission Shift Lock Control

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the automatic transmission shift lock control system. Refer to «Checking Aftermarket Accessories»(ref-188239-S05717410232005090100000) in Wiring Systems.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Shift Lever Does Not Move with Brake Pedal Depressed (Century)»(/buick/century/vi-1997-2005/remont/automatic-trans/#shift-lock-control-system__shift-lever-does-not-move-with) or «Shift Lever Does Not Move with Brake Pedal Depressed (Regal)»(/buick/century/vi-1997-2005/remont/automatic-trans/#shift-lock-control-system__shift-lever-does-not-move-with)
2. «Shift Lever Can Be Moved without Brake Pedal Depressed (Century)»(/buick/century/vi-1997-2005/remont/automatic-trans/#shift-lock-control-system__shift-lever-can-be-moved-without) or «Shift Lever Can Be Moved without Brake Pedal Depressed (Regal)»(/buick/century/vi-1997-2005/remont/automatic-trans/#shift-lock-control-system__shift-lever-can-be-moved-without)

Shift Lever Does Not Move with Brake Pedal Depressed (Century)

Shift Lever Does Not Move with Brake Pedal Depressed (Century)

Shift Lever Does Not Move with Brake Pedal Depressed (Regal)

Shift Lever Does Not Move with Brake Pedal Depressed (Regal)

Shift Lever Can Be Moved without Brake Pedal Depressed (Century)

Shift Lever Can Be Moved without Brake Pedal Depressed (Century)

Shift Lever Can Be Moved without Brake Pedal Depressed (Regal)

Shift Lever Can Be Moved without Brake Pedal Depressed (Regal)

Scheme 403

1. Remove the knee bolster. Refer to «Knee Bolster Replacement»(ref-188255-S40911521812005090100000) in Instrument Panel, Gages and Console.
2. Disconnect the electrical connector from the automatic shift lock control actuator.
3. Remove the automatic shift lock control actuator from the steering column ball studs.

Installation Procedure

1. Install the automatic shift lock control actuator onto the steering column ball studs.
2. Connect the electrical connector to the automatic shift lock control actuator.
3. Adjust the automatic shift lock control actuator. Pull out the tab (1) on the adjuster block side (2) of the actuator. Press on the adjuster block (2) in order to compress the internal adjuster spring and disengage the adjuster teeth. Slide the adjuster block as far away from the actuator as possible. Lock in place by pushing in on the tab (1).
4. Inspect the actuator. The actuator must lock the shift lever clevis when you place the clevis in the park position. If you can move the shift lever without pressing on the brake pedal, readjust the actuator.
5. Install the knee bolster. Refer to «Knee Bolster Replacement»(ref-188255-S40911521812005090100000) in Instrument Panel, Gages and Console.

The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components

1. The automatic transmission shift lock control solenoid
2. The automatic transmission shift lock control switch
3. The brake to shift relay
4. The body control module (BCM)
5. The powertrain control module (PCM)

With the ignition in the ON position, voltage is supplied to automatic transmission shift lock control switch and the brake to shift relay coil through the shift lock control voltage supply circuit. The body control module (BCM) supplies a ground for the brake to shift relay when the body control module (BCM) receives a class 2 message from the powertrain control module (PCM) indicating the transmission is in the PARK position. This closes the normally open contacts of the brake to shift relay and grounds the automatic transmission shift lock control solenoid. The normal close contact of the automatic transmission shift lock control switch allows voltage to the automatic transmission shift lock control solenoid. With the brake to shift relay closed the automatic transmission shift lock control solenoid energizes physically locking the shift lever in the PARK position. When the brake pedal is pressed the contacts in the automatic transmission shift lock control switch open, de-energizing the automatic transmission shift lock control solenoid. This allows the shift lever to be move out of the PARK position.

Park Lock Control System (Regal)

The park lock control system is a safety device that prevents an inadvertent shift out of PARK when the ignition is OFF. The system consists of the following components

1. The automatic transmission park lock solenoid
2. The brake to shift relay
3. The body control module (BCM)
4. The powertrain control module (PCM)

With the ignition in the OFF position the park lock control solenoid is de-energized. This mechanically locks the shift lever in the PARK position. With the ignition in the ON position, battery voltage is supply to the park lock control solenoid. The control circuit of the park lock solenoid is provided a ground through the brake to shift relay when energized. The body control module (BCM) supplies a ground for the brake to shift relay when the body control module (BCM) receives a class 2 message from the powertrain control module (PCM) indicating the transmission is in the PARK position. This closes the normally open contacts of the brake to shift relay and grounds the park lock control solenoid. This energizes the park lock control solenoid releasing the mechanical park lock.

See also:
• Diagnostic System Check - Automatic Transmission Shift Lock Control
• Symptoms - Automatic Transmission Shift Lock Control
• Automatic Transmission Shift Lock Control Connector End Views
• Shift Lever Does Not Move with Brake Pedal Depressed (Century)
• Shift Lever Can Be Moved without Brake Pedal Depressed (Century)